亚麻木酚素提取物对糖尿病小鼠肾脏氧化应激的影响

目的观察亚麻木酚素提取物对糖尿病小鼠早期肾损伤的影响并探讨其作用机制.方法雄性ICR小鼠分六组正常对照组;糖尿病模型对照组;糖尿病模型亚麻木酚素提取物[600 mg/(kg·d)、1.2 g/(kg·d)、3.6 g/(kg·d)]治疗组;糖尿病小鼠盐酸二甲双胍[100 mg/(kg·d)]治疗组.连续灌胃8周,实验末比较各组体重、肾重、肾重/体重、24 h尿白蛋白排泄率、肾组织MDA含量及肾组织SOD、GSH-Px活性.HE染色观察肾小球病理形态学改变.结果与糖尿病模型对照组比较,亚麻木酚素提取物中、高剂量组降低肾重、24 h尿白蛋白排泄率(P＜0.05),且提高肾脏组织SOD、GSH-Px活性,降低MDA含量.结论亚麻木酚素提取物能减轻糖尿病小鼠肾脏损伤,其机制可能与其减轻肾脏氧化应激有关.     

亚麻木酚素提取工艺的研究

目的：通过对不同提取条件的优化,确定从亚麻籽中提取木酚素的方法。方法：分别采用乙醇加热回流提取、乙醇超声提取、甲醇加热回流提取、甲醇超声提取等不同方法提取亚麻籽中木酚素;通过C18柱进行纯化,并对精制产品进行分析鉴定。结果：乙醇超声提取法优于其它法;精制产品中SECO含量为20.1 g/100 g。结论：乙醇超声提取后采用C18柱分离可有效获得亚麻木酚素。     

HPLC法测定亚麻籽中开环异落叶松脂素的含量

目的：建立亚麻籽中开环异落叶松脂素（SECO）含量测定的高效液相色谱分离（HPLC）分析法。方法：采用正交试验考察甲醇浓度、盐酸酸水解温度、时间、浓度对提取开环异落叶松脂素的影响，以HPLC法为含量测定方法。结果：最佳提取开环异落叶松脂素的溶剂系统为质量分数为90％的甲醇，盐酸酸水解温度、时间、浓度分别为90℃、1h、3．5mol／L。HPLC法测定SECO的线性范围在14．8—74μg／ml，相关系数为0．9998。亚麻籽中测定开环异落叶松脂醇酚的含量为1．56mg／g，相对标准偏差为3．47％，加标回收率为88．97％～103．42％。结论：此法简单、快速、经济，是测定亚麻籽中开环异落叶松脂素的有效方法。     

雷公藤多苷对糖尿病大鼠肾小球足细胞病变的保护作用

目的探讨雷公藤多苷(TWP)对糖尿病肾病(DN)大鼠足细胞病变及肾皮质nephrin蛋白表达的影响,为糖尿病的治疗提供实验依据。方法建立高脂饮食联合链脲佐菌素(STZ)诱导DN大鼠模型,按随机数字表法分为DN组13只,小剂量TWP组(每天8 mg/kg)13只和大剂量TWP组(每天16 mg/kg)14只,并以正常大鼠为对照组(n=15)。干预12周后检测大鼠24 h尿蛋白量、血肌酐值(SCr)、尿素氮(BUN)、血糖(Glu)、肾质量/体质量的变化,并以光学显微镜及电子显微镜观察肾脏组织病理改变;免疫荧光法检测肾皮质nephrin蛋白表达。用SPSS 13.0统计软件进行单因素方差分析。结果与对照组大鼠[(0.06±0.02)mg]比较,DN组大鼠24 h尿蛋白[(1.87±0.12)mg]明显增加,差异有统计学意义(P<0.01),TWP干预可显著减少糖尿病大鼠尿蛋白排泄,小剂量和大剂量TWP组尿蛋白分别为(0.98±0.21)、(0.33±0.11)mg,与DN组比较,差异均有统计学意义(P<0.05),此效应与TWP干预剂量相关,大剂量TWP组尿蛋白较小剂量TWP组下降更明显,差异统计学意义(P<0.05)。病理结果显示,DN组表现为肾小球体积增大,基底膜增厚,系膜基质显著增多,足细胞足突增宽、融合、细胞减少;TWP组大鼠肾小球、小管间质及足细胞病变明显减轻。免疫组化结果显示,DN组大鼠肾脏皮质nephrin蛋白表达[每个肾小球平均(2.35±1.75)个]较对照组大鼠肾脏皮质nephrin蛋白表达[每个肾小球平均(18.24±2.89)个]明显减少,差异有统计学意义(P<0.01),而TWP组大鼠肾脏皮质nephrin蛋白表达增加,差异有统计学意义(P<0.01),且小剂量TWP组[每个肾小球平均(11.34±1.56)个]与大剂量TWP组[每个肾小球平均(15.27±2.03)个]的差异有统计学意义(P<0.05)。结论 TWP干预可缓解DN大鼠足细胞病变,肾皮质nephrin蛋白表达上调可能在该保护机制中发挥作用。     

亚麻木酚素对去卵巢大鼠血脂水平的影响

目的研究亚麻木酚素(secoisolariciresinol diglucoside,SDG)对去卵巢大鼠血脂水平的影响。方法以8w龄雌性SD大鼠为研究对象,根据体重随机分为4组,分别为假手术组(SHAM)、去卵巢对照组(OVX)、低剂量和高剂量亚麻木酚素组(L-SDG、H-SDG)。手术后高脂饲料喂养1w,然后每日灌胃给予不同浓度的SDG。每2w取动物尾血分离血清测定血脂含量,喂养8w后处死大鼠,采集重要脏器称重并对子宫样本进行病理分析。结果与去卵巢对照组相比,高剂量的SDG(75mg/kg bw.d)对去卵巢引起的大鼠子宫萎缩有一定的抑制作用。SDG对去卵巢大鼠的肝脏、脾脏、双肾的脏体比均无显著影响(P>0.05),但能使大鼠的胸腺脏体比显著增加(P<0.05);显著升高血清高密度脂蛋白水平(P<0.05),对低密度脂蛋白没有影响(P>0.05),高剂量SDG可显著降低血清总胆固醇水平(P<0.05)。结论 SDG对高脂饲料喂养的去卵巢SD大鼠的子宫萎缩有一定的抑制作用并能增加胸腺重量,对血脂水平有一定的调节作用。     

足细胞损伤在糖尿病肾病中作用机制的研究进展

糖尿病肾病是糖尿病患者最主要的微血管并发症之一,患病率可达到20%～40%,是导致终末期肾病的最主要原因之一。糖尿病肾病主要是由于肾小球高滤过、系膜细胞增生、基底膜增厚、肾小球肥大、细胞基质积累等原因所致,进一步导致肾小管的纤维化和肾小球的硬化。近年来,关于DN患者尿蛋白与足细胞的功能和形态改变有着密切联系的研究越来越多。在DN早期,由于足细胞的足突消失和融合,且随着病情进展,足细胞损伤积累可导致凋亡与脱落的发生、肾小球基底膜受到破坏、大量蛋白尿产生,促进DN进展为ESRD。因此,研究清楚足细胞的损伤机制将有助于为糖尿病肾病患者的治疗提供新策略。     

足细胞标志蛋白检测在糖尿病肾病中的临床应用价值

目的 检测糖尿病肾病(DN)患者足细胞标志蛋白(PCX)表达的变化,并探讨其相关的临床意义. 方法 选择DN患者68例(DN组),按尿白蛋白与肌酐比值分为三个亚组:正常蛋白尿组(＜ 30mg/g,A组)、微量白蛋白尿组(≥30 mg/g而＜300 mg/g,B组)、大量白蛋白尿组(≥300 mg/g,C组).另选择健康体检者20例作为对照组,酶联免疫吸附试验法检测尿沉渣中PCX表达水平. 结果 DN组患者尿沉渣中PCX、血肌酐、血尿素氮的表达水平显著高于对照组[(27.44±6.87) μg/L比(3.52±1.13) μg,/L、(154.82±11.54) μmol/L比(82.56±5.71)μmol/L、(8.79±0.58) mmol/L比(4.23±0.34) mmol/L,P＜0.01];A、B、C组PCX的表达水平分别为(18.04±4.12)、(23.58±5.43)、(32.18±6.05)μg/L,差异均有统计学意义(P＜0.05);A、B、C组血肌酐、血尿素氮分另为 (138.54±8.66)、(142.16±11.74)、(165.13±12.85) μmol/L,(8.48±0.43)、(8.56±0.61)、(10.04±1.17) mmol/L,血肌酐、血尿素氮在A组和B组比较差异无统计学意义(P＞0.05),但在A组和C组、B组和C组比较差异有统计学意义(P＜0.05).结论 DN患者尿沉渣中存在PCX的高表达,检测PCX有利于DN患者肾损害的早期诊断和病变程度的评估.     

亚麻木酚素对去卵巢大鼠缺血再灌注损伤心肌细胞凋亡相关蛋白表达的影响

目的 探讨亚麻木酚素主要活性成分开环异落叶松树酯酚二葡萄糖苷（SDG）干预对雌性去卵巢大鼠心肌缺血再灌注损伤后心肌细胞凋亡相关蛋白表达的影响。方法 选取SPF级健康SD雌性10周龄大鼠50只,按照体重随机分为2组,分别为未去卵巢组、去卵巢组,去卵巢组又分为缺血再灌注假手术组、缺血再灌注组、SDG干预组、雌二醇干预组。SDG干预组采用蒸馏水溶解SDG在50 mg/kg.体重 剂量下灌胃,雌二醇干预组采用0.8 mg/kg.体重 剂量进行灌胃,其余组均采用等量蒸馏水灌胃,共灌胃60 d。采用western blot对Bcl-2、Bax、 BAD、p-BAD蛋白进行检测。结果 与缺血再灌注假手术组比较,缺血再灌注明显使去卵巢大鼠的Bcl-2/Bax水平降低、Bad/p-Bad水平升高,SDG干预后,去卵巢大鼠心肌组织Bcl-2/Bax水平增高、Bad/p-Bad水平降低。结论 SDG可以通过下调Bad/p-Bad水平以及上调Bcl2/Bax水平来发挥对心肌缺血再灌注损伤后的保护作用。     

AMPK信号转导：对糖尿病肾病足细胞的生物学意义

糖尿病肾病是糖尿病的主要长期并发症之一,是最常见的终末期肾脏疾病的原因。肾小球基底膜增厚、肾小球细胞肥大、足细胞丢失是糖尿病肾病中主要的病理改变,并最终引发蛋白尿。足细胞是肾小球滤过屏障的重要组成部分,足细胞损伤是糖尿病肾病的发展关键因素。失调的AMP活化激酶蛋白是一种重要的细胞能量传感器,可能在这一过程中起着至关重要的作用。本综述的目的是为了强调AMPK相关的分子机制在糖尿病肾病足细胞病的发病过程中所起的作用。     

开环异落叶松树脂酚对乳腺癌MCF-7细胞增殖的影响

目的研究开环异落叶松树脂酚(SECO)及其代谢产物肠内酯(ENL)、肠二醇(END)对人乳腺癌MCF-7细胞株增殖的影响,揭示其可能的作用机制。方法采用四甲基偶氮唑盐(MTT)比色法测定SECO、END与ENL对MCF-7细胞增殖的影响,并与染料木黄酮(GEN)进行对比。采用光学显微镜与流式细胞仪(FCM)检测了MCF-7细胞生长过程中受到的影响,分析了SECO抗乳腺癌的作用机制。结果低浓度SECO对MCF-7细胞增殖起促进作用,高浓度SECO对MCF-7细胞增殖起明显的抑制作用;呈现G2/M期阻滞。光学显微镜观察到细胞凋亡的形态。ENL与END则在不同浓度下均表现出抑制作用。结论SECO对MCF-7细胞的增殖具有浓度依赖效应,其抑制MCF-7细胞增殖作用可能与其代谢产物有关。     

Effects of dietary flaxseed lignan extract on symptoms of benign prostatic hyperplasia

A flaxseed lignan extract containing 33% secoisolariciresinol diglucoside (SDG) was evaluated for its ability to alleviate lower urinary tract symptoms (LUTS) in 87 subjects with benign prostatic hyperplasia (BPH). A randomized, double-blind, placebo-controlled clinical trial with repeated measurements was conducted over a 4-month period using treatment dosages of 0 (placebo), 300, or 600 mg/day SDG. After 4 months of treatment, 78 of the 87 subjects completed the study. For the 0, 300, and 600 mg/day SDG groups, respectively, the International Prostate Symptom Score (IPSS) decreased -3.67 +/- 1.56, -7.33 +/- 1.18, and -6.88 +/- 1.43 (mean +/- SE, P = .100, < .001, and < .001 compared to baseline), the Quality of Life score (QOL score) improved by -0.71 +/- 0.23, -1.48 +/- 0.24, and -1.75 +/- 0.25 (mean +/- SE, P = .163 and .012 compared to placebo and P = .103, < .001, and < .001 compared to baseline), and the number of subjects whose LUTS grade changed from "moderate/severe" to "mild" increased by three, six, and 10 (P = .188, .032, and .012 compared to baseline). Maximum urinary flows insignificantly increased 0.43 +/- 1.57, 1.86 +/- 1.08, and 2.7 +/- 1.93 mL/second (mean +/- SE, no statistical significance reached), and postvoiding urine volume decreased insignificantly by -29.4 +/- 20.46, -19.2 +/- 16.91, and -55.62 +/- 36.45 mL (mean +/- SE, no statistical significance reached). Plasma concentrations of secoisolariciresinol (SECO), enterodiol (ED), and enterolactone (EL) were significantly raised after the supplementation. The observed decreases in IPSS and QOL score were correlated with the concentrations of plasma total lignans, SECO, ED, and EL. In conclusion, dietary flaxseed lignan extract appreciably improves LUTS in BPH subjects, and the therapeutic efficacy appeared comparable to that of commonly used intervention agents of alpha1A-adrenoceptor blockers and 5alpha-reductase inhibitors.     

Dietary flaxseed lignan extract lowers plasma cholesterol and glucose concentrations in hypercholesterolaemic subjects

Lignans, derived from flaxseed, are phyto-oestrogens being increasingly studied for their health benefits. An 8-week, randomised, double-blind, placebo-controlled study was conducted in fifty-five hypercholesterolaemic subjects, using treatments of 0 (placebo), 300 or 600 mg/d of dietary secoisolariciresinol diglucoside (SDG) from flaxseed extract to determine the effect on plasma lipids and fasting glucose levels. Significant treatment effects were achieved (P < 0.05 to < 0.001) for the decrease of total cholesterol (TC), LDL-cholesterol (LDL-C) and glucose concentrations, as well as their percentage decrease from baseline. At weeks 6 and 8 in the 600 mg SDG group, the decreases of TC and LDL-C concentrations were in the range from 22.0 to 24.38 % respectively (all P < 0.005 compared with placebo). For the 300 mg SDG group, only significant differences from baseline were observed for decreases of TC and LDL-C. A substantial effect on lowering concentrations of fasting plasma glucose was also noted in the 600 mg SDG group at weeks 6 and 8, especially in the subjects with baseline glucose concentrations > or = 5.83 mmol/l (lowered 25.56 and 24.96 %; P = 0.015 and P = 0.012 compared with placebo, respectively). Plasma concentrations of secoisolariciresinol (SECO), enterodiol (ED) and enterolactone were all significantly raised in the groups supplemented with flaxseed lignan. The observed cholesterol-lowering values were correlated with the concentrations of plasma SECO and ED (r 0.128-0.302; P < 0.05 to < 0.001). In conclusion, dietary flaxseed lignan extract decreased plasma cholesterol and glucose concentrations in a dose-dependent manner.     

Dose effects of flaxseed and its lignan on N-methyl-N-nitrosourea-induced mammary tumorigenesis in rats

Dietary supplementation with flaxseed or its lignan secoisolariciresinol diglycoside (SDG) has reduced dimethylbenz[a]anthracene-induced mammary tumor size and number in rats. The objective of this study was to determine whether flaxseed has a dose-dependent effect on N-methyl-N-nitrosourea (MNU)-induced mammary tumor promotion and whether this effect can be attributed to its SDG. Two days after injection with MNU (50 mg/kg body wt i.p.), female Sprague-Dawley rats were fed a high-fat (20% soybean oil) AIN-93G basal diet alone (BD) or supplemented with flaxseed (2.5% F and 5% F) or SDG by gavage [SDG in 2.5% F (LSDG) and SDG in 5% F (HSDG)] for 22 weeks. Although tumors tended to be smallest in the 5% F group throughout the experimental period, flaxseed feeding did not significantly affect tumor size, multiplicity, or incidence in comparison to BD. However, there was a dose-dependent effect of SDG on tumor multiplicity. Tumor multiplicity was lowest in the HSDG group and highest in the LSDG group throughout treatment (p < 0.05), indicating that HSDG inhibited, whereas LSDG promoted, MNU-induced mammary tumor development. Tumor invasiveness and grade were decreased in all treatment groups compared with the BD (p < 0.032). Thus, although flaxseed feeding had no significant effect on tumor growth indexes, flaxseed and SDG treatment, regardless of dose, appeared to delay the progression of MNU-induced mammary tumorigenesis. Disparities between this study and previous studies on flaxseed may be related to differences in experimental design, the use and dose of a different carcinogen, and protective effects by the alpha-linolenic acid present in the BD.     

Effect of Picrorrhiza rhizoma extracts on early diabetic nephropathy in streptozotocin-induced diabetic rats

The hypoglycemic effect of an aqueous extract of Picrorrhiza Rhizoma (PR) was investigated on diabetic nephropathy. The body weight of each of eight rats per group was measured 7 days after streptozotocin (STZ) treatment. The blood glucose levels 3 days after STZ treatment and the changes in body weight, kidney weight, blood glucose levels, and serum blood urea nitrogen (BUN) were also measured, and the histopathology of the kidney was examined. Body weight decreases and increases of kidney weight, blood glucose levels, and serum BUN and creatinine levels were detected in the diabetic control with histopathological changes related to diabetic nephropathy in the kidney. However, the level of hyperglycemia was significantly lowered in all groups given the PR extract. In addition, the changes related to diabetic nephropathy with the body weight were also significantly lower in the captopril and all PR extract-dosing groups than in the diabetic control. In conclusion, an aqueous extract of PR has relatively good inhibitory effects on STZ-induced diabetes with early diabetic nephropathy with a similar efficacy to an equal dose of captopril.     

Effect of flaxseed and wheat bran on serum hormones and lignan excretion in premenopausal women

OBJECTIVE: To examine the effects of flaxseed consumption (a lignan-rich plant food) alone and in combination with wheat bran on serum hormones and urinary lignan excretion in premenopausal women. METHODS: Sixteen subjects were studied for four feeding treatments lasting two menstrual cycles each in a randomized, crossover design. During each treatment, subjects consumed their habitual diets supplemented with baked goods containing no flaxseed or wheat bran, 10 g of flaxseed, 28 g of wheat bran, or 10 g of flaxseed plus 28 g of wheat bran/day. Serum samples collected during the mid-luteal phase of the second menstrual cycle of each diet treatment were analyzed for serum hormones and sex hormone binding globulin. Urine samples collected during the same time period were analyzed for urinary lignan excretion. RESULTS: There were no changes in serum hormone concentrations or sex hormone binding globulin on any of the treatments. Urinary lignan excretion significantly increased on diet treatments that included flaxseed, but inclusion of wheat bran did not significantly alter lignan excretion. CONCLUSIONS: Urinary lignan excretion increased with flaxseed consumption, but serum hormones did not change in this group of premenopausal women. Consumption of wheat bran with flaxseed did not alter urinary lignan excretion associated with flaxseed consumption.     

葛根素对糖尿病肾病大鼠细胞间黏附分子-1基因表达的调控

目的观察葛根素对糖尿病大鼠肾小球细胞间黏附分子ICAM-1基因表达的调控。方法利用链脲佐菌素腹腔注射法诱导建立1型糖尿病大鼠模型,将实验用SD大鼠随机分为正常对照组、糖尿病组、葛根素治疗组。治疗16周。观察治疗期间及治疗后大鼠的一般状况、血糖、尿素氮、血肌苷,内生肌苷清除率、24 h尿蛋白排泄率,原位杂交检测肾组织CD54基因表达。结果造模组大鼠均出现肾脏功能有损害;葛根素能改善基本状况,降低糖尿病大鼠的尿素氮、血肌苷、24 h尿白蛋白排泄率,增加内生肌苷清除率,细胞间黏附分子mRNA表达显著下调。结论葛根素具有确切的肾脏保护作用。     

Effect of compound Puerarin on the collage IV in streptozotocin-induced diabetic nephropathy rats

OBJECTIVE: To observe the effect of compound Puerarin on collagen IV of streptozotocin-induced diabetic rats. METHODS: Diabetic nephropathy rats were induced by intraperitoneal injection of streptozotocin (STZ). Rats were allocated randomly to control group (10), diabetes model group (10), Vitamin C group (10), Puerarin group (10), vitamin C plus Puerarin group (10). The study period lasted for 12 weeks. During and after the treatment, the general state, blood glucose levels, glycosylated hemoglobin, blood urea nitrogen, serum collagen IV, blood urea nitrogen, serum creatinine, urinary albumin excretion rate of the 24-hour, and clearance rate of creatinine collagen IV protein were determined by immunohistochemistoche analysis as well as type the gene expression of collagen IV alpha 1 mRNA were determined by in situ hybridization analysis in the kidney tissue of different groups. RESULTS: (1) Diabetes mellitus and renal function lesion occurred in the four groups. (2) Vitamin C and Puerarin could improve the general conditions of diabetic Rats, decrease blood urea nitrogen [(8.68 +/- 0.43), (7.98 +/- 0.47) and (5.76 +/- 0.82) micromol/L, serum creatinine [(74.68 +/- 8.20), (75.52 +/- 7.98) and (58.66 +/- 6.65) mmol/L], and urinary albumin excretion rate of the 24-hour [(18.40 +/- 0.37), (17.24 +/- 0.30) and (9.97 +/- 1.27) mg/24 h x 10(-3)]; increase clearance rate of creatinine [(0.59 +/- 0.21), (0.61 +/- 0.14) and (0.69 +/- 0.32) ml/min], the expression of collage IV absorbance [(111.56 +/- 14.61), (110.78 +/- 9.69) and (95.44 +/- 9.97) ] in the diabetic Rats were significantly inhibited at the same time. CONCLUSION: The compound Puerarin might have some functions on preventing ren by inhibiting expression of type IV collagen.     

复方葛根素对糖尿病肾病Ⅳ型胶原的作用

目的 观察复方葛根素对糖尿病大鼠肾小球Ⅳ型胶原(IV-C)表达的影响.方法 利用链脲佐菌素腹腔注射法诱导建立1型糖尿病大鼠模型,将实验用SD大鼠按照数字表法随机分为正常对照组(10只)、糖尿病组(10只)、葛根素治疗组(10只)、维生素C治疗组(10只)、维生素C和葛根素联合治疗组(10只).治疗12周,观察治疗期间及治疗后大鼠的一般状况、血糖、尿素氮、血肌酐,内生肌酐清除率、糖化血红蛋白、血清Ⅳ-C、24 h尿蛋白排泄率,免疫组化检测肾组织Ⅳ-C蛋白表达,原位杂交检测肾组织Ⅳ-Cα1基因表达.结果 (1)4个糖尿病大鼠模型组大鼠均出现肾脏功能损害;(2)葛根素和维生素C能改善基本状况,降低糖尿病大鼠(葛根素治疗组、维生素C治疗组、联合治疗组)的尿素氮[(8.68±0.43)、(7.98±0.47)和(5.76±0.82)μmol/L]、血肌酐[(74.68±8.20)、(75.52±7.98)和(58.66±6.65)mmol/L]、24 h尿白蛋白排泄率[(18.40±0.37)、(17.24±0.30)和(9.97±1.27)mg/24 h×10-3];增加内生肌酐清除率[(0.59±0.21)、(0.61±0.14)和(0.69±0.32)ml/min];Ⅳ-C、[(111.56±14.61),吸光度显著下调(110.78±9.69)和(95.44±9.97)].结论 复方葛根素可能通过抑制Ⅳ-C的表达,具有确切的肾脏保护作用.     

Exposure to purified lignan from flaxseed (Linum usitatissimum) alters bone development in female rats

Due to the potential oestrogenic effects of secoisolariciresinol diglycoside (SDG), the mammalian lignan precursor in flaxseed (Linum usitatissimum), we hypothesized that exposure to purified SDG during early life would have a positive effect on developing bone. This present study determined whether exposure to SDG purified from flaxseed during suckling via mother's milk or continuously to adolescence (postnatal day (PND) 50) or adulthood (PND 132) increased bone mineral content (BMC) or bone strength in female rat offspring. Offspring were exposed to basal diet (BD) or one of two doses of SDG (50S, 100S) equivalent to that in a 50 or 100 g flaxseed/kg diet during lactation only or through to PND 50 or 132. At PND 50 and 132, femurs were analysed for BMC by dual energy X-ray absorptiometry and biomechanical strength by a 3-point bending test. Compared with BD group, rats exposed to continuous 50S or 100S diet had stronger femurs at PND 50 without changes in BMC. At PND 132 there were no differences in femur strength despite the fact that continuous exposure to BD resulted in a higher BMC than rats exposed to 100S during lactation only or to 50S or 100S during lactation through to adulthood. In conclusion, female rat bone is more sensitive to the oestrogen-like action of lignans during early life when endogenous levels of sex hormones are low, but by adulthood the improved bone strength does not persist. Importantly, exposure to purified lignan does not have negative effects on bone strength.